1. How do we know the age of objects on Earth? ESS: 1-6 Apply scientific reasoning and evidence from ancient materials to construct an account of Earth’s early history

2. Reading: Radiometric Dating Text Ch. 12.3 (347-350) Usgs.gov  Search radiometric dating

3. Videos: Radiometric Dating http://www.sciencechannel.com/tv-shows/greatest-discoveries/videos/100-greatest- discoveries-radiometric-dating/ http://www.sciencechannel.com/tv-shows/greatest-discoveries/videos/100-greatest- discoveries-radiometric-dating/ http://www.pbs.org/wgbh/nova/tech/radiocarbon-dating.html https://www.youtube.com/watch?v=zzJF31Y2-rc https://www.youtube.com/watch?v=dv9vOobpstg

4. M&M Half-Life Lab

5. Intro to lab 1.Define the following terms… – Radiometric dating – Decay – Half-life – Parent-isotope – Daughter-isotope 2.Read Directions. 3.This will be done in groups of about 3.

6. M&M Decay Table Run (Half life) Number Atoms in Parent Isotopes Class average Group 1Group 2Group 3Group 4Group 5Group 6Group 7Group 8 0 1 2 3 4 5 6 7 8

7. Number of Half-Lives Number of Parent Isotopes M&M Half-Lives

9. ES Radiometric Dating Quiz tinyurl.com/esquiz12 1. Use the M&Ms and the Half Life Graph to solve the questions. Red= Carbon 12 Yellow= Carbon 14 Half Life of Carbon 12=5700 years If you found an old fossil sample that had 5 red and 5 yellow in it, estimate how old it is based on the decay of Carbon 12 to Carbon 14

10. ES Radiometric Dating Quiz 2. How old would a fossil be if you had 2 reds and 8 yellows? Red=Carbon 12 Yellow=Carbon 14 Carbon 12 Half life= 5700 years

11. ES Radiometric Dating Quiz 3. How old would the fossil be if you had 1 red and 99 yellows? Red= C-12 Yellow= C-14 Half Life C12=5700 years

12. ES Quiz 12 4. Based on your answers from #1-3, what are some weaknesses of carbon 14 dating of old objects?

13. ES Quiz 12 Blue= Uranium Green= Lead Half Life Uranium= 704 Million Years 5. How old is a rock sample that has 4 blues and 6 greens?

14. ES Quiz 12 Blue= Uranium Green= Lead Half Life Uranium= 704 Million Years 6. How old is a rock sample that has 1 blue and 9 green?

15. ES Quiz 12 7. Why is Uranium decaying into lead better for finding out the age of the Earth? 8. Why is Carbon 12 decaying into Carbon 14 better for dating living things? 9. Why has Nuclear weapons testing weakened the radiometric dating of rocks? 10. Why is Carbon-14 dating going to become unreliable for future uses due to unnatural levels of carbon in the environment?